Common Diamond Buying Mistakes

Often, a customer will shop for a diamond using a traditional jeweler, even if they eventually purchase online. The buyer is able to see various diamond sizes, shapes, and qualities first hand; allowing for a more informed and confident online purchase (aware that "actual" images shown online are often nothing of the sort). In some cases, the customer may decide to purchase from the local jeweler based on their service and selection. In either case, when shopping for a diamond at a traditional jeweler, keep the following in mind:

The number one mistake made when purchasing a diamond is to be misled on cut quality. Cut is more difficult to define than color or clarity, and therefore often ignored or misrepresented. Common issues include:

Being shown two or three diamonds of various cut qualities, in an effort to sell the best of the available options. While the customer may choose the best option shown, it is not necessarily a well cut diamond. It is simply the best of what is currently available at that particular store.
Purchasing a deeply cut diamond. A deeply cut diamond carries more of its carat weight "hidden" in the depth of the diamond as opposed to the width. These poorly cut diamonds are less expensive per carat, and are common in most jewelry stores. A customer might purchase a 1.00 carat diamond that actually looks like a .90 carat diamond because it is too deeply cut.
Because well cut diamonds are more expensive per carat than fair or good cuts, few are carried in traditional jewelry stores. Less than well cut diamonds cost less to purchase, less to inventory, can be sold at a lower price, and turn more quickly in the jeweler's inventory - so the incentive to carry them is overwhelming.

FTC guidelines for jewelry retailers state that any seller-stated color or clarity grade must be within 1 grade of what it is appraised at by a qualified independent appraiser. This means that if you purchase a diamond that the seller represents as G / VS2, and it later appraises as H / SI1, you have no legal recourse with the jeweler. Unfortunately, this leeway encourages jewelers to inflate their grades; a jeweler who is confident he has a G color diamond is free to represent it as an F.

It is impossible to accurately judge the clarity and color of a diamond once it is set. Flaws are easily hidden under prongs, and color is obscured by the reflections from the setting itself. Unless it is GIA certified, do not purchase a diamond over $2,000 without seeing it loose (preferably with a magnifier), so that you can see firsthand what you are getting.

Color grading is notoriously difficult. GIA goes to great lengths to create standardized environments and training for color grading. Do not accept the jeweler's grade as a substitute. While color grading for small accent diamonds is commonly given in ranges (e.g. G-H color); for a center diamond, accept only reputable lab grading. If a jeweler gives a color range on a center diamond (e.g. "This diamond is color grade G / H") you can be sure the diamond has not been graded by any lab, much less GIA, and the color grade is not reliable.

Master Set for Diamond Color Grading.

If you have doubts about the color grade you are given on a diamond, ask the jeweler if you can compare it to his in-house master color set. A master color set is a standardized set of cubic zirconia stones showing the various color grades. By holding your diamond up to the master set, you should be able to see where it fits on the GIA color spectrum.

Without a master set, or other objective measure, be very careful when comparing color in diamonds. By making invalid comparisons, a jeweler can often sell a customer up on color. For example, a customer is shown two diamonds, one described as "G" color, one described as "H" color; the customer sees that the color distinction is obvious, and decides they should move to the higher color. However, problems with this approach include:

The customer does not know if both diamonds are GIA color graded. Do not perform any comparison without first seeing the actual certificates for the diamonds in question.
The customer may be comparing two different shapes. Body color shows more readily in certain diamond shapes; for example, comparing an H emerald with a G round will yield a more pronounced color difference than comparing two rounds or two emeralds.
The customer does not know if both diamonds are the same cut quality. Cut quality affects the brightness, and therefore perceived color of a diamond. When compared to a good cut H, an excellent cut G will have a more pronounced color improvement than if two like cuts are compared. In determining cut grade, do not take the seller's word. Use the GIA cut grade for round diamonds, and for fancies carefully compare the depth, table, symmetry, and fluorescence of the two diamonds prior to allowing a color comparison.

Jewelry store lighting is designed to make diamonds look their best (for example, using specialized lighting to emit a spectrum shifted towards blue will make a yellow diamond appear whiter). When considering any diamond, ask to see the diamond in normal lighting, meaning out from under the spotlights. Options include taking the diamond outside the showroom area where standard office lighting is prevalent, or to a skylight, atrium, window or direct sunlight. You will want to see how your diamond looks under these conditions since they will be the norm once you own the diamond.

Be aware that diamond carat weights are often rounded up. For instance, a .69 carat diamond might be described as 3/4 carat. While this is an accepted norm non-certified diamonds (e.g. earrings and small accents), it is not acceptable for a certified or primary diamond. Always ask for the exact carat weight, and the price per carat, so that you can easily and accurately compare diamonds.

Ask to see a copy of the GIA Grading Report for any diamond you are considering. Do not purchase from a jeweler who is unwilling or unable to show you the certificate for a diamond prior to purchase. (Learn more about certification.)

Understand the distinction between a GIA certified diamond and a diamond that has been certified by a GIA trained gemologist. In the first case, the diamond has been graded at an independent GIA facility, in a standardized environment, by GIA technicians who have issued a GIA grading report for the diamond. In the second case, the diamond has been graded by a jewelry store employee who has been trained by GIA. The diamond has no GIA certification, and it is unlikely that the diamond was actually graded in strict accordance with GIA standards.

Remember that roughly 1/3 of diamonds have been treated in some way (Lumera does not sell treated diamonds). While these treatments may make a diamond look better, they can have a negative impact on both the value and stability of the stone. One benefit of diamonds certified by a reputable lab is that any treatment will be prominently disclosed. Without this disclosure, it is impossible for the average customer to recognize a treated diamond.

Often, diamonds (and settings) offered in a jewelry store have no price tag, only a style number or bar code. Alternatively, the jeweler may have a price printed, but use a calculator to figure the discount on each diamond you ask about. Both situations allow the retailer to adjust the price on the spot, based on what he believes you are willing to pay. Be very careful, as the retailer has more experience and more information than you do.

Diamonds virtually never sell for less than their true market value. Sales and coupons do not offer the opportunity to purchase a diamond for less than its value, only for less mark-up than the days it is not on sale. Traditional jewelry stores carry a much higher mark-up on diamonds than do online retailers. However, in return you receive face to face service and a chance to see the diamond before you buy.

Jeweler Warranties And Guarantees

Most jewelers offer a set of warranties and/or guarantees with every purchase. While return and trade-in guarantees are valuable (provided there is no fine print), other offers may be of less value than they first appear. When reviewing a jeweler's policies, always:

Ask to see any warranty or guarantee in writing prior to purchase. A surprising number of jeweler's guarantees are not actually in writing.
Confirm exactly what your warranty covers besides the standard free cleanings and inspections. Though they may at first appear to, most guarantees do not cover loss, theft, or damage. A jeweler's warranty almost never takes the place of insurance. Most agreements also do not cover the cost of any work required as a result of a free inspection. Most also become void if another jeweler repairs, alters, or even cleans the item covered by the agreement.
Know that while some agreements do provide value, the ultimate purpose of most is to insure your loyalty (by prohibiting other jewelers from working with your item) and repeat visits (for the free cleaning and inspections).
Know your obligations under any agreement. Often the cleanings and inspections are not only free; they are required to keep the warranty in force. Carefully note what is required of the purchaser to maintain the warranty.

Protecting Your Diamond After The Purchase

If you need to leave your diamond with a jeweler (to have it set in a ring, or to have an existing ring cleaned or repaired), but are concerned about the (remote) possibility that the jeweler may switch your diamond for a diamond of lesser value, take one or more of the following precautions:

Example of GIA laser inscription

If your diamond is inscribed with the GIA (or other laboratory) certificate number, make sure to note the location of the inscription so that you can find it again when the diamond is returned to you. Mention the inscription to the jeweler; this will not only alert the jeweler to the fact that you are aware of this security feature, it will also insure that when setting or repairing the ring the inscription is not inadvertently obscured or damaged.
Ask the jeweler to show you the diamond's inclusions with a magnifier before you leave it with him. Compare what you see under a loupe with the markings on your certificate (if your certificate does not have a diamond plot of inclusions ask the jeweler to make a simple sketch of the position and type of inclusions). Thank the jeweler for his help as you will now be able to reliably identify your diamond when you pick it up, and in the future. This will remove any temptation on the jeweler's part to switch your diamond.
If your diamond is of very high value, take it to an independent appraiser before you leave it with anyone else. Have the appraiser review the diamond and put the findings in writing. Return to the same appraiser after leaving the diamond with any third party. The appraiser can briefly re-examine the diamond to confirm that it is the same one as originally appraised.